This is exactly what I am trying to create too. See my post. http://www.raspberrypi.org/phpBB3/viewt ... 61#p248261
The route I was going to go was with webdav, as you can stream movies to ipads and iphones without fully downloading them first. I have this set up on my server at home, which works perfectly.
This is my first pi project, and so far the only thing I have done is bought a wifi dongle from fleabay. I know it is a realtek chipset, but not sure which one, so hopefully it might be ap compatible.
Good luck, and keep us up to date on how you manage